Google's net income was $2.89 billion, or $8.62 per share during the final three months of last year. That compared to net income of $2.71 billion, or $8.22 per share, at the same time last year.

Excluding items but including Motorola Home, the company earned $10.59 per share, up from $9.50 a share in the year-earlier period.

Revenue including Motorola Home increased 50 percent to $12.16 billion from $8.13 billion a year ago.

Analysts had expected the company to report earnings ex-items of $10.42 a share on $12.34 billion in revenue, according to a consensus estimate from Thomson Reuters.

Average cost-per-click, a critical metric that denotes the price advertisers pay Google, declined 6 percent from a year ago, the fifth consecutive quarter of decline, but increased about 2 percent over the third quarter of 2012.

Google executives told analysts on a conference call that the company had focused on improving the metric — shoring up margins — while lowering the overall growth rate of paid clicks in the holiday quarter.

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"The core business is a great business and the fourth-quarter is always a time for Google to shine," said Colin Gillis, an analyst at BGC Financial. "However, Motorola is still losing money and click rates still declined. They only declined 6 percent, but go back four or five quarters and click prices were improving. So mobile is still pressuring click prices."

Although the average cost per click declined, aggregate paid clicks rose roughly 24 percent over the comparable period and 9 percent compared to the previous quarter.

Investors will be paying close attention to clues about the company's position in the mobile market, an area seen as crucial by analysts as smartphones become more dominant, and its reported advertising revenue per click.

This quarter, Google said it is treating its Motorola Home unit as "discontinued operations" and separating the group's results from the rest of its businesses in its earnings release. This switch has sparked some confusion among Wall Street analysts, many of whom are still including Motorola Home in their estimates for Google's earnings.

Correction:

An earlier version of this story had Google earnings ex-items at $10.65 a share. In fact, the comparable number to analysts' estimates is $10.59 a share, which includes a loss of six cents a share at its Motorola Home unit, which was sold in December. Analysts' estimates were excluding items but still included Motorola Home.